Variable speed multi-channel pulsato rotor



Aug. 16, 1966 D. J. LESLIE 3,266,592

VARIABLE SPEED MULTI-GHANNEL PULSATO ROTOR Filed on. 22, 1965 5Sheets-Sheet 1 4 39 33 Go 3a 1/ I 40 flrroervsys.

Aug. 16, 1966 D. J. LESLIE VARIABLE SPEED MULTI-CHANNEL PULSATO ROTORFiled 001.. 22, 1965 5 Sheets-Sheet 2 ammo/v POWER ZINE mfihw @4 Z Z m ms/aA/AL SOURCE 6, 1966 D. J. LESLIE 3,266,592

VARIABLE SPEED MUL'I'I-CHANNEL PULSATO ROTOR Filed Oct. 22, 1965 5Sheets-Sheet 5 V SIG/VAL I0! I08 I09 I I04 invention. in the drawingsaccompanying and forming part of the United States Patent 3,266,592VARIABLE SPEED MULTI-CHANNEL PULSATO ROTOR Donald J. Leslie, Altadena,Calif. Electro Music, P.(). Box 2267B) Filed Oct. 22, 1965, Ser. No.502,121 9 Claims. (Cl. 181-27) This invention relates to acousticapparatus for producing pulsato, and of a type shown and described in byprior Patent No. 2,489,653. In this apparatus, rotary sound channels areprovided that produce a sound radiation pattern that recurs at a raterequired to produce the characteristic pulsato effect. The requisiterate of recurrence is about to 8 cycles per second.

If a single sound channel is rotated, then the required angular velocityis about 400 cycles per minute. This imparts a substantial peripheralvelocity to the opening of the sound channel, and a correspondinglylarge frequency deviation. If the speed is reduced to half, then thefre- "quency deviation is likewise reduced; the rate of cyclicrecurrence of the sound radiation pattern is also reduced to about 3 or4 cycles per second, and the characteristic pulsato is lost. In order torestore the pulsato effect, two sound channels supplied by the sameacoustic or electrical source must be used in 180 spacial relationshipabout the rotational axis.

The organist at times desires a full rich pulsato of the type obtainedby rotating a single channel at 400 cycles per minute, and at othertimes desires a muted pulsato such as obtained by rotating two channelsat 200 cycles, or three channels at about 133 cycles, etc. For example,a full pulsato may be appropriate for use with flute, tibia and stoppeddiapason tones; but only a lesser frequency deviation may be appropriatefor string and reed tones.

The primary object of this invention is to provide a single pulsatoapparatus capable of producing these various types of pulsato. Anotherobject of this invention is to provide pulsato apparatus of thischaracter in which a number of rotary sound channels are provided on acommon support, and wherein a speed change is automatically accompaniedby a change in the operative number of sound channels, thus ensuringthat the rate of recurrence of the sound radiation pattern (asdistinguished from the rate of rotation) is maintained in order toproduce the trically, and slip rings .are used in order to conduct theelectrical signals to the rotary apparatus. In the latter case, thenumber of control leads increases, and more complicated slip ringstructures appear necessary. Another object of this invention is toprovide a system of this character in which the electrical or acousticswitching is accomplished automatically within the framework of therotary apparatus, all in response to a change in speed of the rotaryapparatus. For this purpose, centrifugal devices are carried with therotary apparatus for operating the acoustic or electrical switches.

This invention possesses many other advantages, and

' has other objects which may be made more clearly apparent from aconsideration of several embodiments of the For this purpose, there areshown a few forms present specification. These forms will now bedescribed Patented August 16, 1966 ice in detail, illustrating thegeneral principles of the invention; but it is to be understood thatthis detailed description is not to be taken in a limiting sense, sincethescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevational view of rotary pulsato apparatusincorporating the present invention;

FIG. 2 is a top plan view of a portion of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view taken along the planecorresponding to line 3--3 of FIG. 2;

FIG. 4 is a top plan view generally similar to FIG. 2, anddiagrammatically illustrating a modified form of the present invention;

FIG. 5 is a fragmentary sectional view taken along the ofifset planecorresponding to line 55 of FIG. 4;

FIG. 6 is a diagrammatic view illustrating a modified form of thepresent invention;

FIG. 7 is a circuit diagram illustrating an alternate switchingarrangement for use in the system shown in FIG. 6;

FIG. 8 is a diagrammatic view of a pulsato rotor incorporating modifiedform of the present invention;

FIG. 9 is a circuit diagram of the relay power circuit; and

FIG. 10 is a circuit diagram of the relay control circuit.

In FIG. 1 there is illustrated a fragmentary part of a cabinet 10. Aninterior support or partition 11, mounts a driver or transducer 12designed to convert the electrical organ signal into sound. In thepresent instance the driver 12 is suspended from a plate 13 thatoverlies an aperture 14 in the partition 11. A horn 15 provides soundchannels registering with the transducer.

A pulley bracket 16 secured to the horn 15 serves as its support, and ismounted for rotation about the axis of the driver 12 by the aid ofbearing 17.

The pulley bracket 16 has a through opening 18 that registers with theoutput of the driver 12. The horn 15 has two sound channels 19 and 20radiating from a common throat 21 that registers with the opening 18 ofthe pulley bracket 16. The outer openings of the channels are spacedfrom the axis of rotation so as to produce orbital motion thereof.

An acoustic switch for closing and opening the channel 20 is provided.This switch is in the form of .a closure plate 22, movable from fullline closed position illustrated in FIG. 3 to the phantom line openposition while the channel 19 remains in communication with the throat.

ing apertures in the sides of the horn.

Rotation of the shafts 23 and 24 in a clockwise direction as viewed inFIG. 3 causes the valve 22 to be positioned across the channel 20adjacent to the throat 21. This movement of the closure is limited by aninterior shoulder 25. Upon movement of the shaft in the opposite angulardirection, thevalve 22 moves into a shallow recess 26 in the upperportion of the horn, thus fully opening the channel 20.

In order to move the valve, a linkage structure is provided. The linkagecomprises a crank 27 that includes two arms 28 and 29 fixed respectivelyto the shafts 23 and 24, and a connecting bar or yoke 30. The arms 28and 29 extend along the sides of the horn, and the bar 30 extends acrossthe top. The arms 28 and 29 lie in a plane offset approximately from thevalve 22. The crank 27 is thus freely reciprocable over the top of thehorn as the closure moves between its limited positions. A tensionspring 31 normally urges the crank 27 in a counterclockwise direction asviewed in FIG. 3 in order to open the channel 20. Thus one end of thespring 31 is afiixed to the connecting bar 30 and its other end to anapertured boss 32 formed on the horn 15. A Weight assembly 33counterbalances the spring 31 and closes the channel before the hornreaches a speed of 400 revolutions per minute.

The weight assembly includes a rocker 34 pivoted on the horn beneath thechannel 20 for movement about an axis parallel to that of the closure22. The rocker 34 has arms 35 and 36 that extend upwardly along oppositesides of the horn and a connecting portion 37. A rod 38 projectingupwardly from the connecting portion 37 adjust-ablymounts a weight 39,as by a set screw 40. The rocker 34 is connected to the crank 27 by theaid of a link 41, pivoted at its ends respectively to the rod 38 and theconnecting bar 30. Accordingly centrifugal force urges the rocker 34 ina clockwise direction as viewed in FIG. 3 to close the valve 22. Whenthe horn is rotated at low speeds, corresponding substantially to about200 cycles per second, the spring 31 overpowers the centrifugal force ofthe weight 39 and causes the channel to be opened.

At low speed, both channels are operative, causing a recurrence in thesound radiation pattern at the rate of approximately 400 cycles persecond. However, when the horn 15 is rotated at about 400 cycle persecond, there is but one operative sound channel 19, and again the rateof recurrence of the sound radiation pattern is 400 cycles per second.In both instances the characteristic pulsato rate is achieved.

In order to rotate the horn 15, the motor 42 is provided (-FIG. 1) thatmay be mounted upon the inside of the cabinet wall10. The motor 42 has apulley 43 connected to the pulley bracket 16 by the aid of a fiexiblebelt 44. The motor 42 may be a two speed motor controlled by a simpledouble throw switch, notshown.

In the form illustrated in FIGS. 4 and 5 a still more versatile pulsatoapparatus is provided. In this instance four sound channels 51, 52, 53,and 54 are provided that are equiangularly spaced about the axis of thedevice. As in the previous form, these sound channels all communicatewith a common throat 55 that registers with the non-rotary transducer.When the horn 50 is rotated at 100 r.p.m., all four channels 51, 52, 53,and 54 are open. When the horn is rotated at 200 r.p.m. two oppositechannels 52 and 53 are closed, whereby only the diametrically disposedchannels 51 and 54 operate. When the horn 50 is rotated at 400revolutions per minute the channels 52, 53 and 54 are closed, and onlythe channel 51 is operative. In all three instances the characteristicrecurrence rate of the sound radiation pattern is about 400 cycle perminute. Yet the intensity of pulsato or frequency deviation issubstantially changed.

In order to close the channels 52, 53, and 54 centrifugal devices areprovided for each channel, substantially in accordance with the formillustrated in the FIGS. 1 to 3.

The only essential difference is that the weights for the channels 52and 53 are substantially increased whereby closure is effected beforethe horn reaches a speed of approximately 200 cycles per second.Optionally, adjustment could be made in the position of the weights orin the spring constants. It will also be understood that the commonlinkage could be provided for operating the valves for both channels 52and 53.

Before the horn reaches a rotational speed of 200 7, cycles per secondthe valves for the channels 52 and 53 close in response to thecentrifugal force of the Weight or weights, the valve for the channel 54remaining open. Before the horn reaches the rotational rate of 400 rpm.the valve for the sound channel 54 also closes. Suitable adjustablespeed motive means may be provided for the horn 50.

In the form illustrated in FIG. 6 a pulsato rotor 60 is illustrated butin this instance mounts to speakers structures 61 and 62 atdiametrically opposite positons thereof. Since the electrical-acoustictransducers associated with the speakers 61 and 62 rotate with the druma slip ring assembly 63 is necessary in order to conduct the organsignal to the speakers from external leads.

The drum 60 is operated by a two speed motor 64 shown as having threeleads 65, 66 and 67. The high speed may be about twice low speed, and byway of example, 380 revolutions per minute. The lead 65 cooperates withone element 68 of a connector cooperable with a power source. The otherleads 66 and 67 respectively connect to contact 69 and 70 of a relaystructure 71. The relay structure 71 includes an arm 72 connected to theother element 69' of the power connector. The arm 72 is engageablealternately with the contact 69 and the contact 70 upon energization orde-energization of a relay coil 73. Thus upon operation of the relaycoil 73, a circuit is effected to the motor by the aid of leads 65 and66, and upon de-energization of the relay coil 73, a connection iseffected to the motor by the aid leads 67 and 65. These alternateconnections provide fast and slow operation by well known means. a

The relay 71 also has contacts 74 and 75 cooperable with an arm 76 fordetermining operation of either one or both of the speakers 61 and 62,all in accordance with the fast or slow operation of the motor 64. Thecontact 74 connects via a brush 77 and one element 78 of the slip ringassembly 63 to one side of the speaker 62. The other contact 75 connectswith one element 79 of a connector to which the organ signal is applied.The arm 76 connects to a brush 80 and through a second element 81 of theslip ring assembly 63 to one side of the speaker 61. The connectorelement 79 cooperable with the signal source also cooperates via a brush82 and slip ring element 83 with the other side of both speakers 61 and62. A

lead 84 joins the other element 85 of the connector to the brush 77 andthe relay contact 74.

When the relay coil 73 is tie-energized and the motor 64 thus operatedat slow speed, both speakers 61 and 62 are connected to the organ outputby the aid of connector elements '79 and 85. The circuit for the speaker62 may be traced as follows: connector element 85, lead 84, brush 77,slip ring assembly element 78, speaker 62, lead 86, slip ring element83, brush 82 and connector element 79. A circuit for speaker 61 may betraced from connector element 85, lead 84, relay contact 74,

- arm 76, brush 80, slip ring element 81, speaker 61, lead 86, slip ringelement 83, brush 82 to the connector 79. When the relay coil 73 isenergized and the motor operated at fast speed, the speaker 61 isremoved from cir cuit and furthermore short-circuited. Thus the circuitfor the speaker 62 remains as before, independent of the relay contacts74 and 75 and arm 76. However, the previous circuit traced for thespeaker 61 via contact 74 is now interrupted, and instead the speaker 61is shortcircuited as follows: relay contact 75, arm 76, brush 80,element 81, speaker 61, lead '86, element 83, brush 82 back to the relaycontact 75. By short-circuiting the speaker 61, currents induced in itscoil damp sympathetic vibrations. Accordingly, no sound issues from thespeaker so short-circuited.

The system of FIG. 6 operates to achieve a recurrence rate of the soundradiation pattern that is the same whether the drum is rotated at low orhigh speed.

In the form of the invention illustrated in FIG. 7, a

switch assembly is carried within the rotary drum. Only two slip ringelements 103 and 104 are provided for conducting the signal from theorgan output. The slip ring elements 103 and 104 respectively cooperatewith leads 105 and 106 across which the speaker 101 is directlyconnected. Thus the speaker 101 is continuously energized independentlyofthe speed of operation of the drum. The speaker 102, however, isconnected across the leads 105 and 106 only when the drum is operated atlow speeds.

Thus the switch 101 includes opposite contacts 107 and 108 and switcharm 109 moved by a centrifugal weight 110. In the full line positioncorresponding to low speed, the cont-act 107 is engaged. This completesthe circuit for the speaker 102 as follows: lead 105, contact 107,switch arm 109, lead 111 to one side of the speaker 102, lead weight 110causes the switch arm 109 to move to the phantom line position and toengage the contact 108. In this position the leads 111 and 112 areconnected together and speaker 102 accordingly is short-circuited.

In the form of the invention illustrated in FIG. 6, two slip ringassemblies, such as shown in my prior Patent No. 3,014,192 may beprovided, one at the top of the rotary apparatus and another at thebottom. Each assembly includes two slip ring elements. Only three of thefour available slip ring elements need be used. In the form illustratedin FIG. '7, only a single two element slip ring assembly is necessary.

In the form illustrated in FIG. 8, drum 150 in this instance mounts sixspeakers 1, 2, 3, 4, 5, and 6, all equiangularly spaced about the axisof the drum. This rotary assembly is designed to operate at any one offour speeds: 66 revolutions per minute with all six speakers connectedto the source; 133 revolutions per minute with only three equiangularlyspaced speakers connected to the source; 200 revolutions per minute withonly two diametrically disposed speakers connected; and finally 400revolutions per minute with only one speaker connected. It will beunderstood of course, that the phase relationship of energization of thespeakers 1, 2, 3, 4, 5, and 6 is all the same, and as more fullyexplained in my prior Patent No. 3,100,024.

In order appropriately to connect the speakers 1 to 6, a centrifugalswitching device 151, carried by the drum 150 is provided. The device151 cooperates with only four external leads, 152, 153, 154, and 155illustrated in FIGS. 9 and 10. These external leads connect to thecentrifugal switch 151 through two slip ring assemblies 156 (FIG. 9) and157 (FIG. The leads 152 and 153 conduct to the slip ring assembly 156,power for operating logic elements to be hereinafter described. Theleads 154 and 155 conduct the electrical output of the organ to the slipring assembly 157. and 159 connect to the external leads through theassembly 157. Across the internal leads, the speaker 1 is permanentlyconnected. The other speakers 2, 3, 4, 5, and 6 are controlled by alogic network carried by the rotor. This network incorporates logicelements in the form of three relays A, B, and C. These relays havecoils 160, 161, and 162 that may be energized by power supplied by leads152 and 153.

The relay coils 160, 161, and 162 are operated in accordance with theposition of the centrifugal switch arm 163. The arm 163 connects throughthe slip ring assembly 156 to one of the power leads 152. A common sideof the relays 160, 161, and 162 all connect through the slip ringassembly 156 to the other of the-power leads 153. The switch arm 163sweeps past a series of contact segments connected to the coils. The arm163 has four defined positions in accordance with the speed of operationof the rotor, and is indicated by the legends. In the first position,corresponding to 66 r.p.m., the arm 163 engages no segments. In the nextposition, corresponding substantially to 133 r.p.m., the arm 163 engagesa segment 164 to energize coil 162 of relay C. At the next position,corresponding substantially to 200 r.p.m., segments 165 and 166 areengaged thus to energize coils 161 and 162 of relays C and B. At thefinal position of the contacting arm 163, corresponding substantially to400 r.p.m., segments 167, 168, and 169 are all engaged resulting inenergization of the coils of all relays C, B and A.

When the arm 166 is at the 66 r.p.m. position circuits Internal leads158' are effected for all speakers. Thus speakers 2 and 6 have a circuitthat includes the normally closed contacts 170 of the relay C. Speakers3 and 5 have a circuit including a normally closed contacts 171 of therelay B. Speaker 4 has -a circuit including normally closed contacts 172of the relay A. Thus all speakers are operative.

When the arm 163 arrives at the 133 r.p.m. position, relay contacts 170open, thus disconnecting speakers 2 and 6 from the leads. Normally openshunt contacts 175 of relay C close to short-circuit both speakers 2 and6. Speakers 3 and 5 remain in circuit due to the fact that relay B isyet de-energized. But speaker 4 is disconnected by virtue of the openingof contacts 172. At the same time a short-circuit path is effected bythe aid of normally opened contacts 176 of relay C and normally closedcontacts 177 of relay B that together shunt speaker 4. Accordinglyequiangularly spaced speakers 1, 3, and 5 operate and thus produce thecharacteristic recurrence rate of the sound radiation pattern.

When the arm 163 moves to the 200 r.p.m. position, relays B and C bothoperate. Speakers 2 and 6 are disconnected as before. Speakers 3 and 5are now also disconnected by virtue of the opening of contacts 171.Shortcircuiting cont-act 179 operated by relay B isolate speakers 3 and5. Speaker 4, however is reconnected through an alternate path thatincludes normally open relay contacts 181 of relay B and normally closedrelay contacts 182 of relay A. At the same time, the short-circuit pathpreviously provided by the relay contacts 176 is operated by operationof the normally closed relay contacts 177. Accordingly diametricallyopposite speakers 1 and 4 operate, and the characteristic recurrencerate for the sound radiation pattern is again produced.

At the third position of the arm 163 all relays operate. Speakers 2, 3,5, and 6 are disconnected as previously described. Speaker 4 is likewisedisconnected by opening of the relay contacts 182. At the same time ashortcircuit path is provided by normally open relay contacts 183operated by relay A.

The segments engaged by the arm 163 have a suitable angular extent toinsure operation despite a slight change or deviation in the speed ofoperation of the drum. It will be understood of course that coupled tothe drum 150 are suitable motive means fior achieving rotation at theselective rates.

The inventor claims:

1. In apparatus for producing acoustic pulsato: a support mounted forrotation about an axis; means forming a plurality of angularly spacedsound channels on the support, said sound channels having sound emittingopenings spaced from the axis of said support; means imparting rotationto the support at selected rates for determining the intensity ofpulsato produced by the sound emitting openings of said channels; andswitching means changing the operative number of sound channels inaccordance with the rate of rotation of said support in order tomaintain substantially constant, the rate of recurrence of the soundradiation pattern produced by said sound channels whereby thecharacteristic pulsato rate is maintained despite changes inthe rate ofrotation of said support.

2. The combination as set forth in claim 1 in which said switching meanscomprises a closure for at least one of said sound channels, andcentripetal-centritugal actuator means carried by said support andcoupled to said closure to open the same below a selected speed and toclose the same above a selected speed.

3. The combination as set forth in claim 1 in which there are fourequiangularly spaced sound channels, said switching means comprising aclosure for three of said channels; first centripetal-centrifugalactuator means for closing the closures of those two of the soundchannels that are diametrically opposite each other, and only when saidsupport reaches a speed of at least about 200 revolutions per minute;and second centripetal-centrifugal actuator means for closing theclosure of the remaining sound channel, and only when said supportreaches a speed of at least about 400 revolutions per minute.

4. 'T he combination as set forth in claim 1 in which a plurality ofspeakers are mounted'on said support and register with said soundchannels respectively; and a switch for determining the rate of rotationof said support; and a common actuatorfor said switch and said switchingmeans.

5. The combination as set forth in claim 1 in which a plurality ofspeakers are mounted on said support and register with said soundchannels respectively and a centripetal-centrifugal actuator mounted onthe support for operating said switching means in accordance with therate of rotation of said support. I

6. The combination as set forth in claim 1 in which a pair of speakersare mounted on said support and register with a pair of sound channelslocated diametrically on said support; slip ring means carries by thesupport and cooperable with external leads connected to the organ outputsaid switching means including a centripetal-centrifugal switch havingone position below a speed of about 400 revolutions per minute, and asecond position at a speed of about 400 revolutions per minute; circuitmeans connecting one of said speakers to said slip ring means anddependent upon said switch being in its said one position; circuit meansshort-circuiting said one of said speakers and dependent upon saidswitch being in its said second position; and circuit means connectingthe other of said speakers to said slip ring means independently of saidswitch.

7 The combination as set forth in claim 1 in which a plurality ofspeakers are mounted on said support and register with said soundchannels respectively; said switching means changing the number or"speakers connected to the signal source; and means for short-circuitingthose speakers disconnected from the signal source for dampingsympathetic vibrations thereof.

8. The combination as set forth in claim 1 in which six speakers areequiangularly mounted on said support and register with said soundchannels respectively; circuit means cooperable with said switchingmeans to connect all of said speakers to a signal source when saidsupport is rotated at a rate of about 66 revolution per minute, toconnect alternate speakers to said signal source when said support isrotated at a rate of about 133 revolutions per minute, to connectdiametrically disposed speakers to said signal source when said supportis rotated at a rate of about 200 revolutions per minute, and to connectonly one of said speakers to said signal source when said support isrotated at a rate of about 400 revolutions per minute.

9. The combination as set forth in claim 8 together with a logic circuitcarried by said support and a speed respon sive element for operatingsaid circuit means.

References Cited by the Examiner UNITED STATES PATENTS I 2,114,6804/1938 Goldsmith 179 -1 3,084,585 4/1963 Wayne s4. 1,24 3,100,024 8/1963Leslie 181-27 LOUIS J. CAPOZI, Primary Examiner.

1. IN APPARATUS FOR PRODUCING ACOUSTIC PULSATO; A SUPPORT MOUNTED FORROTATION ABOUT AN AXIS; MEANS FORMING A PLURALITY OF ANGULARLY SPACEDSOUND CHANNELS ON THE SUPPORT, SAID SOUND CHANNELS HAVING SOUND EMITTINGOPENINGS SPACED FROM THE AXIS OF SAID SUPPORT; MEANS IMPARTING ROTATIONTO THE SUPPORT AT SELECTED RATES FOR DETERMINING THE INTENSITY OFPULSATO PRODUCED BY THE SOUND EMITTING OPENINGS OF SAID CHANNELS; ANDSWITCHING MEANS CHANGING THE OPERATIVE NUMBER OF SOUND CHANNELS INACCORDANCE WITH THE RATE OF ROTATION OF SAID SUPPORT IN ORDER TOMAINTAIN SUBSTANTIALLY CONSTANT, THE RATE OF RECURRENCE OF THE SOUNDRADIATION PATTERN PRODUCED BY SAID SOUND CHANNELS WHEREBY THECHARACTERISTIC PULSATO RATE IS MAINTAINED DESPITE CHANGES IN THE RATE OFROTATION OF SAID SUPPORT.